Many battery operated electronic devices are known for their portability and low powered operation. However, several electronic devices such as notebook computers, radio communication devices, and power tools, to name a few, have progressed to a comparable level of performance as their non-portable counterparts. This increase in performance has led to higher power consumption by these devices. The higher power consumption is partially expended as excess heat. Since users handle these electronic devices, their external surface temperatures can become uncomfortable or even unsafe. When near maximum power is expended by the electronic device, potentially severe burns may result. Manufacturers, however, generally only regulate the temperatures internal to these high-powered electronic devices to prevent internal component damage. Often the external case temperature is ignored. It is up to the user of these devices to decide whether to use an electronic device if it gets too hot. When the user determines that the electronic device is too hot, the user turns the computer off and thus the electronic device can only provide intermittent use.
In the case of notebook computers, in particular, intermittent use is not tolerable so manufacturers have begun to further limit the internal temperatures to prevent the external surface temperatures from getting too hot for the user to operate. Often times, this limit on internal temperatures causes the notebook computer to operate at a lower speed, thus delivering less performance. Since the regulation of the internal temperature is then always performed, the notebook computer may not be operating at it theoretical peak performance.
Besides the potential to burn users, several other serious problems can occur due to hot surface temperatures. One anecdotal story tells of an airline passenger who had difficulty returning his tray to its `full, upright position`. His notebook computer had melted the tray and it fused to the plastic case of the notebook. In another instance, a user had operated his notebook computer on a countertop and after removing the notebook, found that the countertop had become discolored (burned) due to the heat from the notebook. Further, when notebook computers are operated on a user's lap, discomfort has been reported due to the excessive heat. Accordingly, manufacturers are becoming concerned about the case surface temperatures and are limiting the computer's performance to keep the surface temperatures from becoming too hot. However, in several environments, such as when docked, notebook computers can be operated at higher speeds and thus higher external case surface temperatures without causing harm. Therefore, a need exists for electronic devices to be more intelligent in managing thermal heat dissipated out of the device.